Londoner Brian Davis might struggle to make the weekend after slumping to a disappointing five-over 75 on his return to Royal St George's.
Davis finished sixth, his best finish in seven attempts, when the Open was last held here at Sandwich in 2003.
But, although a bit tidier coming home in 36 after going to the turn in four-over 39, he made just one solitary birdie - at the par-four 15th.
Fellow Londoner Andrew Johnston carded a four-over 74 on his Open debut.
Bogeys at 5 and 9 came either side of a run of three straight birdies which took him to the turn in one-under 34.
But he then dropped five shots in four holes from the 11th, three of them at the par-four 459-yard 13th before a birdie/bogey finish.
"I caught a few bad breaks out there which was frustrating as we had good conditions in the afternoon," he told BBC Sport.
"On nine I was looking at a three and ended up with a five and I lost momentum but you never give up, especially not at an Open," admitted the cheery 22-year-old North Londoner, who was last in but goes out again on Friday at the more hospitable time of 1110 BST.
"I'm always going to have a smile on my face playing at the Open."
By contrast, US Tour regular Davis did not have the best of the day's conditions.
"That was hugely disappointing," he told BBC Sport. "Go 10 shots behind after the first round and you're struggling.
"I didn't get it close front nine at all, then hit a couple of bad shots and, all of a sudden, you're not just plodding along, you start making bogeys.
"And I missed a three-and-half footer on the last which summed it all up."
US-based Davis shot a 64 in Texas to win a rain-reduced US final quallfying by a shot to make it to Sandwich.
But, after his enjoyable experience here in 2003, he knows he's got to improve when he tees off for his second round on Friday (1443 BST).
"I've got to bounce back," he said. "But it's not easy on a course like this. It's more severe than somewhere like St Andrews.
"It's very different to when we played it in 2003, having moved some of the tees.
"You miss it on the wrong side and even if you're only three or four yards off, then you make bogey or even double."